/*
 * Licensed to the Apache Software Foundation (ASF) under one or more
 * contributor license agreements.  See the NOTICE file distributed with
 * this work for additional information regarding copyright ownership.
 * The ASF licenses this file to You under the Apache License, Version 2.0
 * (the "License"); you may not use this file except in compliance with
 * the License.  You may obtain a copy of the License at
 * 
 *      http://www.apache.org/licenses/LICENSE-2.0
 * 
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package org.apache.xerces.dom;

import org.apache.xerces.impl.dv.xs.XSSimpleTypeDecl;
import org.apache.xerces.impl.xs.XSComplexTypeDecl;
import org.apache.xerces.xni.NamespaceContext;
import org.apache.xerces.xs.XSTypeDefinition;
import org.w3c.dom.Attr;
import org.w3c.dom.DOMException;



/**
 * ElementNSImpl inherits from ElementImpl and adds namespace support.
 * <P>
 * The qualified name is the node name, and we store localName which is also
 * used in all queries. On the other hand we recompute the prefix when
 * necessary.
 * 
 * @xerces.internal
 * 
 * @author Elena litani, IBM
 * @author Neeraj Bajaj, Sun Microsystems
 * @version $Id: ElementNSImpl.java 924245 2010-03-17 11:58:14Z mrglavas $
 */
public class ElementNSImpl
    extends ElementImpl {

    //
    // Constants
    //

    /** Serialization version. */
    static final long serialVersionUID = -9142310625494392642L;
    static final String xmlURI = "http://www.w3.org/XML/1998/namespace";

    //
    // Data
    //

    /** DOM2: Namespace URI. */
    protected String namespaceURI;

    /** DOM2: localName. */
    protected String localName;

    /** DOM3: type information */
    // REVISIT: we are losing the type information in DOM during serialization
    transient XSTypeDefinition type;

    protected ElementNSImpl() {
        super();
    }
    /**
     * DOM2: Constructor for Namespace implementation.
     */
    protected ElementNSImpl(CoreDocumentImpl ownerDocument,
                            String namespaceURI,
                            String qualifiedName)
        throws DOMException
    {
        super(ownerDocument, qualifiedName);
        setName(namespaceURI, qualifiedName);
    }

	private void setName(String namespaceURI, String qname) {

		String prefix;
		// DOM Level 3: namespace URI is never empty string.
		this.namespaceURI = namespaceURI;
		if (namespaceURI != null) {
            //convert the empty string to 'null'
			this.namespaceURI =	(namespaceURI.length() == 0) ? null : namespaceURI;
		}

        int colon1, colon2 ;

        //NAMESPACE_ERR:
        //1. if the qualified name is 'null' it is malformed.
        //2. or if the qualifiedName is null and the namespaceURI is different from null,
        // We dont need to check for namespaceURI != null, if qualified name is null throw DOMException.
        if(qname == null){
				String msg =
					DOMMessageFormatter.formatMessage(
						DOMMessageFormatter.DOM_DOMAIN,
						"NAMESPACE_ERR",
						null);
				throw new DOMException(DOMException.NAMESPACE_ERR, msg);
        }
        else{
		    colon1 = qname.indexOf(':');
		    colon2 = qname.lastIndexOf(':');
        }

		ownerDocument.checkNamespaceWF(qname, colon1, colon2);
		if (colon1 < 0) {
			// there is no prefix
			localName = qname;
			if (ownerDocument.errorChecking) {
			    ownerDocument.checkQName(null, localName);
			    if (qname.equals("xmlns")
			        && (namespaceURI == null
			        || !namespaceURI.equals(NamespaceContext.XMLNS_URI))
			        || (namespaceURI!=null && namespaceURI.equals(NamespaceContext.XMLNS_URI)
			        && !qname.equals("xmlns"))) {
			        String msg =
			            DOMMessageFormatter.formatMessage(
			                    DOMMessageFormatter.DOM_DOMAIN,
			                    "NAMESPACE_ERR",
			                    null);
			        throw new DOMException(DOMException.NAMESPACE_ERR, msg);
			    }
			}
		}//there is a prefix
		else {
		    prefix = qname.substring(0, colon1);
		    localName = qname.substring(colon2 + 1);
		    
		    //NAMESPACE_ERR:
		    //1. if the qualifiedName has a prefix and the namespaceURI is null,
		    
		    //2. or if the qualifiedName has a prefix that is "xml" and the namespaceURI
		    //is different from " http://www.w3.org/XML/1998/namespace"
		    
		    if (ownerDocument.errorChecking) {
		        if( namespaceURI == null || ( prefix.equals("xml") && !namespaceURI.equals(NamespaceContext.XML_URI) )){
		            String msg =
		                DOMMessageFormatter.formatMessage(
		                        DOMMessageFormatter.DOM_DOMAIN,
		                        "NAMESPACE_ERR",
		                        null);
		            throw new DOMException(DOMException.NAMESPACE_ERR, msg);
		        }
		        
		        ownerDocument.checkQName(prefix, localName);
		        ownerDocument.checkDOMNSErr(prefix, namespaceURI);
		    }
		}
	}

    // when local name is known
    protected ElementNSImpl(CoreDocumentImpl ownerDocument,
                            String namespaceURI, String qualifiedName,
                            String localName)
        throws DOMException
    {
        super(ownerDocument, qualifiedName);

        this.localName = localName;
        this.namespaceURI = namespaceURI;
    }

    // for DeferredElementImpl
    protected ElementNSImpl(CoreDocumentImpl ownerDocument,
                            String value) {
        super(ownerDocument, value);
    }

    // Support for DOM Level 3 renameNode method.
    // Note: This only deals with part of the pb. CoreDocumentImpl
    // does all the work.
    void rename(String namespaceURI, String qualifiedName)
    {
        if (needsSyncData()) {
            synchronizeData();
        }
		this.name = qualifiedName;
        setName(namespaceURI, qualifiedName);
        reconcileDefaultAttributes();
    }

    //
    // Node methods
    //



    //
    //DOM2: Namespace methods.
    //

    /**
     * Introduced in DOM Level 2. <p>
     *
     * The namespace URI of this node, or null if it is unspecified.<p>
     *
     * This is not a computed value that is the result of a namespace lookup based on
     * an examination of the namespace declarations in scope. It is merely the
     * namespace URI given at creation time.<p>
     *
     * For nodes created with a DOM Level 1 method, such as createElement
     * from the Document interface, this is null.
     * @since WD-DOM-Level-2-19990923
     */
    public String getNamespaceURI()
    {
        if (needsSyncData()) {
            synchronizeData();
        }
        return namespaceURI;
    }

    /**
     * Introduced in DOM Level 2. <p>
     *
     * The namespace prefix of this node, or null if it is unspecified. <p>
     *
     * For nodes created with a DOM Level 1 method, such as createElement
     * from the Document interface, this is null. <p>
     *
     * @since WD-DOM-Level-2-19990923
     */
    public String getPrefix()
    {

        if (needsSyncData()) {
            synchronizeData();
        }
        int index = name.indexOf(':');
        return index < 0 ? null : name.substring(0, index);
    }

    /**
     * Introduced in DOM Level 2. <p>
     *
     * Note that setting this attribute changes the nodeName attribute, which holds the
     * qualified name, as well as the tagName and name attributes of the Element
     * and Attr interfaces, when applicable.<p>
     *
     * @param prefix The namespace prefix of this node, or null(empty string) if it is unspecified.
     *
     * @exception INVALID_CHARACTER_ERR
     *                   Raised if the specified
     *                   prefix contains an invalid character.
     * @exception DOMException
     * @since WD-DOM-Level-2-19990923
     */
    public void setPrefix(String prefix)
        throws DOMException
    {
        if (needsSyncData()) {
            synchronizeData();
        }
        if (ownerDocument.errorChecking) {
            if (isReadOnly()) {
                String msg = DOMMessageFormatter.formatMessage(DOMMessageFormatter.DOM_DOMAIN, "NO_MODIFICATION_ALLOWED_ERR", null);
                throw new DOMException(
                                     DOMException.NO_MODIFICATION_ALLOWED_ERR,
                                     msg);
            }
            if (prefix != null && prefix.length() != 0) {
                if (!CoreDocumentImpl.isXMLName(prefix,ownerDocument.isXML11Version())) {
                    String msg = DOMMessageFormatter.formatMessage(DOMMessageFormatter.DOM_DOMAIN, "INVALID_CHARACTER_ERR", null);
                    throw new DOMException(DOMException.INVALID_CHARACTER_ERR, msg);
                }
                if (namespaceURI == null || prefix.indexOf(':') >=0) {
                    String msg = DOMMessageFormatter.formatMessage(DOMMessageFormatter.DOM_DOMAIN, "NAMESPACE_ERR", null);
                    throw new DOMException(DOMException.NAMESPACE_ERR, msg);
                } else if (prefix.equals("xml")) {
                     if (!namespaceURI.equals(xmlURI)) {
                         String msg = DOMMessageFormatter.formatMessage(DOMMessageFormatter.DOM_DOMAIN, "NAMESPACE_ERR", null);
                         throw new DOMException(DOMException.NAMESPACE_ERR, msg);
                     }
                }
            }

        }
        // update node name with new qualifiedName
        if (prefix !=null && prefix.length() != 0) {
            name = prefix + ":" + localName;
        }
        else {
            name = localName;
        }
    }

    /**
     * Introduced in DOM Level 2. <p>
     *
     * Returns the local part of the qualified name of this node.
     * @since WD-DOM-Level-2-19990923
     */
    public String getLocalName()
    {
        if (needsSyncData()) {
            synchronizeData();
        }
        return localName;
    }
    
    /**
     * NON-DOM
     * Returns the xml:base attribute.
     */
    protected Attr getXMLBaseAttribute() {
        return (Attr) attributes.getNamedItemNS("http://www.w3.org/XML/1998/namespace", "base");
    } // getXMLBaseAttribute():Attr

    /**
     * @see org.w3c.dom.TypeInfo#getTypeName()
     */
    public String getTypeName() {
        if (type !=null){
            if (type instanceof XSSimpleTypeDecl) {
                return ((XSSimpleTypeDecl) type).getTypeName();
            } else if (type instanceof XSComplexTypeDecl) {
                return ((XSComplexTypeDecl) type).getTypeName();
            }
        }
        return null;
    }

    /**
     * @see org.w3c.dom.TypeInfo#getTypeNamespace()
     */
    public String getTypeNamespace() {
        if (type !=null){
            return type.getNamespace();
        }
        return null;
    }

    /**
     * Introduced in DOM Level 2. <p>
     * Checks if a type is derived from another by restriction. See:
     * http://www.w3.org/TR/DOM-Level-3-Core/core.html#TypeInfo-isDerivedFrom
     * 
     * @param typeNamespaceArg 
     *        The namspace of the ancestor type declaration
     * @param typeNameArg
     *        The name of the ancestor type declaration
     * @param derivationMethod
     *        The derivation method
     * 
     * @return boolean True if the type is derived by restriciton for the
     *         reference type
     */
    public boolean isDerivedFrom(String typeNamespaceArg, String typeNameArg, 
            int derivationMethod) {
        if(needsSyncData()) {
            synchronizeData();
        }
        if (type != null) {
            if (type instanceof XSSimpleTypeDecl) {
                return ((XSSimpleTypeDecl) type).isDOMDerivedFrom(
                        typeNamespaceArg, typeNameArg, derivationMethod);
            } else if (type instanceof XSComplexTypeDecl) {
                return ((XSComplexTypeDecl) type).isDOMDerivedFrom(
                        typeNamespaceArg, typeNameArg, derivationMethod);
            }
        }
        return false;
    }    

    /**
     * NON-DOM: setting type used by the DOM parser
     * @see NodeImpl#setReadOnly
     */
    public void setType(XSTypeDefinition type) {
        this.type = type;
    }
}
